Generally, digital device users carry a mobile phone at all times when commuting while in a mobile environment. Also, the digital device users use a diary, a personal digital assistant (PDA), a computer, and the like in order to manage various types of schedules. When attending a meeting, the digital device users generally carry a diary and a notebook computer. Also, the digital device users carry multiple credit cards in their wallet.
However, when carrying various types of devices, it may be very inconvenient to carry many devices at one time and also it may be very difficult to be aware of operational procedures of the devices.
Currently, boundary breakdown between communication devices and computing devices accelerates a convergence phenomenon in portable terminals and also brings technical developments that include various types of contents in a single terminal using unification of technologies for portable terminal components. However, since a product model is generally manufactured based on a one-sided point of view from terminal manufactures, advancements in the field of portable terminals using an all-in-one scheme may not satisfy various types of demands from consumers. Also, general users desire simplicity and slimness of a digital device in order to improve the portability of the digital device. However, as more functions are included in software or the digital device, the general users need to be aware of even a function that the general users may not need to know about in reality. Therefore, it is inconvenient for the general users to use the digital device in their daily lives. Also, the general users have no choice but to purchase a portable terminal embedded with unsatisfactory and unnecessary contents for their own personal preference. In this case, the users may have a potential cost burden.